Process for treating aqueous solutions containing industrial wastes

ABSTRACT

A treatment zone 10 in the form of a basin 12 having an inlet port 14 and an outlet port 16. The inlet port 14 allows water to flow into the basin 12. The outlet port 16 allows water to flow out of the basin 12. The inlet port 14 and the outlet port 16 are located at opposite ends of the basin 12 so as to allow water from a body of water having a concentration of water soluble metal ions contained therein to flow substantially through the entirety of the basin 12. A porous matrix 22 is disposed within the treatment zone 10. The porous matrix 22 is inoculated with a population of aerobic metal oxidizing bacteria. The population of aerobic metal oxidizing bacteria is capable of metabolizing water soluble metal ions in the water from the body of water into water insoluble metal oxides. Thus, there is an overall decrease in the concentration of the metal ions in the water flowing out of the treatment zone 10 as compared to water flowing into the treatment zone 10. The water flow out of the treatment zone also has a higher pH than the water flowing into the treatment zone.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part application of U.S.patent application Ser. No. 08/169,741, filed Dec. 17, 1993, now U.S.Pat. No. 5,441,741, which is a file wrapper continuation application ofU.S. patent application Ser. No. 07/912,814, filed Jul. 13, 1992.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process for reducing theconcentration of water soluble metals in aqueous solutions, and, inparticular, to a process for removing iron and/or manganese ions fromaqueous solutions such as mine discharge waters or spent leaching watersprior to discharging such waters into surface or ground water systems.

2. Description of the Prior Art

The quality of water in the United States is important for the healthand the quality of life of the people who live therein. For more than ahundred years the quality of water has been reduced by industrialpollution and deep mining, and, more recently, surface mining. Deep andsurface mining pollution of water systems have been especially prevalentin the coal-producing regions of the Appalachian mountains. Thepollutants resulting from these types of mining operations include iron,sulfate, manganese, aluminum, and acidity, to name a few. The toxicityof these pollutants impact both health and recreation in those regions.

A current method that is used to reduce the ionic and acidic pollutionfrom the water systems around mining operations consists of raising thepH of the water above 8.5 with caustic soda. Ions then precipitate fromthe solution as hydroxides and a high pH supernatant is then dischargedinto streams. This process requires continuous maintenance andreplenishment of caustic soda.

Recently, microorganisms have been used to reduce the concentration ofpollutants from both industrial wastes and mine discharges. There havebeen many reports that bacteria can be used to remove metals as sulfidesand sulfates from industrial and mining wastes.

It has been shown that sulfate can be removed using sulfate reducingbacteria in an anaerobic system (see U.S. Pat. No. 4,124,501 by Yen etat. and U.S. Pat. No. 4,200,523 by Balmat). Using similar methodology,sulfate reducing bacteria grown under anaerobic conditions has beenshown to yield hydrogen sulfide gas which precipitates out metals asmetal sulfides (see U.S. Pat. No. 4,354,937 by Hallberg). Also, in U.S.Pat. No. 4,789,478, Revis et at. used a mixed culture of Citrobacterfreundii and sulfate reducing bacteria so as to precipitate heavy metalions into sulfide form. Furthermore, in U.S. Pat. No. 4,522,723,Kauffman et at. were able to precipitate out metals into sulfide speciesusing sulfate reducing bacteria of the genera Desulfovibro andDesulfotomaculum.

Another approach was taken by Lupton et at. in U.S. Pat. No. 5,062,956.Using anaerobic sulfate reducing bacteria, they were able to precipitatechromium as an insoluble hydroxide since the removal of sulfate causes arise in pH. Similarly, in U.S. Pat. No. 4,519,912, Kauffman et al. wereable to remove sulfate and heavy metals from aqueous solutions usingmixed cultures of anaerobic bacteria of the genus Clostridium and atleast one other bacteria from the genera Desulfovibrio andDesulfotomaculum. Kauffman et at. used a treatment zone to carry out theremoval of water soluble species of heavy metals including selenium andsulfate ions. Analogously, in U.S. Pat. No. 4,519,913, Baldwin et al.disclosed the use of a porous matrix for retaining a population ofbacterium of the genus Clostridium thereby reducing the concentration ofwater soluble ionic selenium species. The bacteria were grown underanaerobic conditions and definitive temperature and pH conditions.

In addition to the anaerobic methods discussed above, there have beenseveral reports of using aerobic microorganisms to reduce theconcentrations of ions in waste water. For example, in U.S. Pat. No.3,923,597, Chakrabarty et al. used a genetically engineered species ofPseudomonas to remove mercury as a pollutant or an impurity. Also, inU.S. Pat. No. 4,468,461, Bopp was able to remove chromate from wastewater using a strain of Pseudomonas fluorescens. Furthermore, in U.S.Pat. No. 4,728,427, Revis et at. were able to reduce the concentrationof at least one heavy metal from an aqueous waste solution using aculture of Pseudomonas maltophilia. Moreover, in U.S. Pat. No.4,898,827, Brierly et al. were able to remove ionic species of Ag, Cu,Pb, Cr, and Ni from waste waters using Bacillus subtilis and in theprocess recover these metals.

It has also been shown that metals can be recovered from aqueoussolutions such as industrial waste water using several species of fungi(see U.S. Pat. No. 4,293,333 by Drobot).

In U.S. Pat. No. 4,530,763, Clyde et al. describe a method for treatingwaste fluids so as to remove selected chemicals with bacteria attachedto porous fiber webbing. The waste fluids, containing nutrients, aredrawn through the porous fiber webbing wherein ions of Cr, Ur, Fe, Ag,Pb, and V are removed from the solution.

Finally, it has been shown that manganese can be chemically removed fromwaste water by the addition of bisulfite to precipitate the manganese asmanganese dioxide (see U.S. Pat. No. 3,349,031 by Hatch et al.).

Although all of the above-discussed methods are directed to treatingwaste water solutions and/or removing contaminants from waste watersolutions, none are directed toward a process for removing iron and/ormanganese ions from an aqueous solution by passing the aqueous solutionthrough a porous matrix that is inoculated with metal oxidizing bacteriaand is maintained under aerobic conditions. The present invention isdirected to such a process.

SUMMARY OF THE INVENTION

The present invention contemplates a process for removing iron and/ormanganese ions from an aqueous solution by passing the aqueous solutionthrough a porous matrix that is inoculated with metal oxidizing bacteriaand is maintained under aerobic conditions. As a result of this process,the pH level of the aqueous solution is significantly increased. Also,as a result of this process, the acidity level of the aqueous solutionis significantly decreased. Furthermore, as a result of this process,the alkalinity level of the aqueous solution is significantly increased.

From the foregoing descriptive summary it is apparent how the presentprocess is distinguishable from the above-mentioned prior art.Accordingly, the primary objective of the present invention is toprovide a process for removing iron and/or manganese ions from anaqueous solution by passing the aqueous solution through a porous matrixthat is inoculated with metal oxidizing bacteria and is maintained underaerobic conditions, and which during said removal, reduces the aciditylevel of the aqueous solution.

Other objectives and advantages of the present invention will becomeapparent to those skilled in the art upon reading the following detaileddescription and claims, in conjunction with the accompanying drawingswhich are appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate a fuller understanding of the present invention,reference is now be made to the appended drawings. The drawings shouldnot be construed as limiting the present invention, but are intended tobe exemplary only.

FIG. 1 is a graph showing the effect of wetland nutrients on bacterialremoval of manganese from water.

FIG. 2 is a graph showing the manganese concentration taken at the inletof the treatment zone compared with the manganese concentration taken atthe outlet of the treatment zone over a seven month period.

FIG. 3 is a graph showing the iron concentration taken at the inlet ofthe treatment zone compared with the iron concentration taken at theoutlet of the treatment zone over a seven month period.

FIG. 4 is a graph showing the pH level of the water at the inlet of thetreatment zone compared with the pH level of the water at the outlet ofthe treatment zone over a seven month period.

FIG. 5 is a graph showing the acidity and the alkalinity levels of thewater at the inlet of the treatment zone compared with the acidity andthe alkalinity levels of the water at the outlet of the treatment zoneover a seven month period.

FIG. 6 is a top plan view of a typical treatment zone that is used toreduce the concentration of water soluble metal species in aqueoussolutions according to the present invention taken along line 6--6 ofFIG. 7.

FIG. 7 is a side plan view of a typical treatment zone that is used toreduce the concentration of water soluble metal species in aqueoussolutions according to the present invention taken along line 7--7 ofFIG. 6.

PREFERRED EMBODIMENT OF THE PRESENT INVENTION

A laboratory experiment was conducted so as to demonstrate how theconcentration of water soluble metals may be reduced in aqueoussolutions according to the present invention. In this laboratoryexperiment, six five-gallon buckets were filled with mine watercontaining 80 parts per million (ppm) manganese. Three of thefive-gallon plastic buckets were filled with mine water that was takendirectly from a mine seep and three of the five-gallon buckets werefilled with mine water that was taken from a mine seep and then passedthrough a man-made cattail wetland. In four of these buckets, twocontaining seep water and two containing wetland water, a porous matrixof limestone shale was added. In two of these buckets, one containingseep water and limestone shale and one containing wetland water andlimestone shale, an aerobic metal oxidizing bacteria, in this case thebacteria Metallogenium, was cultured on the porous matrix of limestoneshale. The contents of all of the buckets were aerated by an aquarianpump and an airstone. Also, all of the buckets were held at atemperature within the range from about 32° F. to about 90° F., but itshould be noted that is preferred that the buckets are held at atemperature within the range from about 50° F. to about 85° F.

The mine seep water was poor in nutrients for the bacteria while thewetland water was rich in nutrients for the bacteria. It should be notedthat the nutrients in the wetland water may include biological breakdownproducts of plant material such as cellulose, hemicellulose,hydrocarbons, pectin and pectin substances, starches, fructans, levans,inulins, sugars, proteins, amino acids, chitin, lignin, organic acids,and derivatives of these materials. It should also be noted that thenutrients in the wetland water may include organic carbon sources suchas yeast extract, malt extract, peptone, and biological and municipalwaste water sludges. It should further be noted that the wetland watermay also contain a trace nutrient such as the B-vitamins peridoxine andthiamine.

Referring to FIG. 1, the results of the laboratory experiment are shownindicating the effect that wetland nutrients have on bacterial removalof manganese from water containing the same. As can be clearly seen inFIG. 1, the most effective removal of manganese occurred in the bucketcontaining wetland water and limestone shale inoculated with the aerobicmetal oxidizing bacteria. However, there was still a reduction ofmanganese in the bucket containing seep water and limestone shaleinoculated with the aerobic metal oxidizing bacteria.

It should be noted that the aerobic metal oxidizing bacteria metabolizesthe manganese on the porous matrix so that manganese may be recovered asa water insoluble oxide of manganese.

A field experiment was also conducted so as to demonstrate how theconcentration of water soluble metals may be reduced in aqueoussolutions according to the present invention. In this field experiment,a treatment zone was constructed comprising a pit having the dimensionsof 100 feet long, 10 feet wide, and 3 feet deep. The pit was locatednext to a man-made cattail wetland containing water having a manganeseion concentration ranging from about 35 ppm to about 45 ppm, an iron ionconcentration ranging from about 0.02 ppm to about 0.32 ppm, a pH levelranging from about 4.5 to about 4.8, an acidity level ranging from about85 mg/l to about 125 mg/l, an alkalinity level ranging from about 4 mg/lto about 6 mg/l, and a rich supply of nutrients for the bacteriaMetallogenium. The pit was filled with a porous matrix of limestoneshale, comprising about two-thirds of the total volume of the pit. Theporous matrix was then inoculated with twenty five-gallon plasticbuckets of aerobic metal oxidizing bacteria, in this case the bacteriaMetallogenium. It should be noted that the porous matrix may becomprised of other materials such as gravel, but an alkaline basedmaterial is preferred.

The inoculum was prepared on limestone shale in the twenty five-gallonplastic buckets using water from the man-made cattail wetland site. Thisenrichment technique provided a steady state population of bacteria thatwere site specific.

After the treatment zone was inoculated with the aerobic metal oxidizingbacteria, water from the man-made cattail wetland was allowed to flowtherethrough. The flow rate of the water through the treatment zone wasabout 2 gallons per minute thereby providing the water with a retentiontime in the treatment zone of about 2.5 days. Considering the dimensionsof the treatment zone, the flow rate of the water through the treatmentzone was about 2 gallons of water per cubic foot of the porous matrixper day. It should be noted that the flow rate of the water through thetreatment zone may be controlled by gravity by properly positioning thetreatment zone with respect to the manmade cattail wetland. It shouldalso be noted that the treatment zone is left uncovered so as to allowthe water to be sufficiently aerated.

Referring to FIG. 2, the manganese concentration taken at the inlet ofthe treatment zone compared with the manganese concentration taken atthe outlet of the treatment zone is shown over a 7 month period. As canbe clearly seen in FIG. 2, there was a significant removal of manganesefrom the water flowing through the treatment zone, even during the coldwinter months. The aerobic metal oxidizing bacteria metabolized themanganese on the porous matrix so that manganese was recoverable as awater insoluble oxide of manganese. It should be noted that themanganese ions in the water were in the Mn (II) and Mn (IV) oxidationstates.

Referring to FIG. 3, the iron concentration taken at the inlet of thetreatment zone compared with the iron concentration taken at the outletof the treatment zone is shown over a 7 month period. As can be clearlyseen in FIG. 3, there was a nearly constant removal of iron from thewater flowing through the treatment zone, even during the cold wintermonths. The aerobic metal oxidizing bacteria metabolized the iron on theporous matrix so that iron was recoverable as a water insoluble oxide ofiron. It should be noted that the iron ions in the water were in the Fe(III) oxidation state.

Referring to FIG. 4, the pH level of the water at the inlet of thetreatment zone compared with the pH level of the water at the outlet ofthe treatment zone is shown over a 7 month period. As can be clearlyseen in FIG. 4, the pH level of the water at the outlet of the treatmentzone was significantly increased from the pH level of the water at theinlet of the treatment zone, even during the cold winter months. The pHlevel change in the water was a result of the aerobic metal oxidizingbacteria interacting with the limestone shale. More specifically, theaerobic metal oxidizing bacteria interact with the limestone shale so asto release calcium carbonate into the water and thereby increase the pHlevel of the water.

Referring to FIG. 5, the acidity and the alkalinity levels of the waterat the inlet of the treatment zone compared with the acidity and thealkalinity levels of the water at the outlet of the treatment zone areshown over a 7 month period. As can be clearly seen in FIG. 5, theacidity level of the water at the outlet of the treatment zone wassignificantly decreased from the acidity level of the water at the inletof the treatment zone, even during the cold winter months. As can alsobe clearly seen in FIG. 5, the alkalinity level of the water at theoutlet of the treatment zone was significantly increased from thealkalinity level of the water at the inlet of the treatment zone, evenduring the cold winter months. The acidity level change in the water wasa result of the aerobic metal oxidizing bacteria interacting with thelimestone shale. More specifically, the aerobic metal oxidizing bacteriainteracts with the limestone shale so as to release calcium carbonateinto the water and thereby decrease the acidity level of the water. Thealkalinity level change in the water was a result of the aerobic metaloxidizing bacteria interacting with the limestone shale. Morespecifically, the aerobic metal oxidizing bacteria interacts with thelimestone shale so as to release calcium carbonate into the water andthereby increase the alkalinity level of the water.

Referring to FIGS. 6 and 7, there is shown a treatment zone 10 similarto the one just described. The treatment zone 10 is in the form of abasin 12 having an inlet port 14 and an outlet port 16. The inlet port14 allows water to flow into the basin 12. The outlet port 16 allowswater to flow out of the basin 12. The inlet port 14 and the outlet port16 are located at opposite ends of the basin 12 so as to allow waterfrom a body of water having a concentration of water soluble metal ionscontained therein to flow substantially through the entirety of thebasin 12. The flow rate of the water from the body of water through thebasin 12 may be controlled by gravity by properly positioning thetreatment zone 10 with respect to the body of water.

The basin 12 also has a plurality of upper flow barriers 18 and aplurality of lower flow barriers 20. These upper and lower flow barriers18, 20 are provided so as to prevent a direct flow path and therebyinsure that the water from the body of water flows substantially throughthe entirety of the basin 12. It should also be noted that the treatmentzone 10 is left uncovered so as to allow the water flowing therethroughto be sufficiently aerated.

A porous matrix 22 is disposed within the treatment zone 10. The porousmatrix 22 is inoculated with a population of aerobic metal oxidizingbacteria. The population of aerobic metal oxidizing bacteria is capableof metabolizing water soluble metal ions in the water from the body ofwater into water insoluble metal oxides. The water insoluble metaloxides are deposited on the porous matrix 22, thereby allowing for theirrecovery. Thus, there is an overall decrease in the concentration of themetal ions in the water flowing out of the treatment zone 10 as comparedto water flowing into the treatment zone 10. It is important to notethat the porous matrix 22 never needs to be regenerated through the useof conditioned water or any other means.

With the present invention treatment zone 10 and corresponding processnow fully described, it can thus be seen that the primary objective setforth above is efficiently attained and, since certain changes may bemade in the above-described treatment zone 10 and corresponding processwithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:
 1. A process for reducing the concentration of water soluble metal ions in an aqueous solution containing the same, said process comprising the steps of:providing an aqueous solution having contained therein a concentration of water soluble metal ions; providing a porous matrix containing cultured populations of aerobic metal oxidizing bacteria from the genus Metallogenium, said bacteria being capable of metabolizing said water soluble metal ions in said aqueous solution into water insoluble metal oxides, said porous matrix being provided under aerobic conditions; and passing said aqueous solution through said porous matrix in a continuous fashion so as to allow said bacteria to metabolize said metal ions in said aqueous solution into water insoluble metal oxides, which are substantially retained on said porous matrix, thereby resulting in a reduction in the concentration of said water soluble metal ions in said aqueous solution.
 2. The process as defined in claim 1, wherein said water soluble metal ions in said aqueous solution are manganese ions in the Mn (II) and Mn (IV) oxidation states and iron ions in the Fe (III) oxidation state.
 3. The process as defined in claim 1, wherein said aqueous solution is mine discharge water.
 4. The process as defined in claim 1, wherein said porous matrix is a porous matrix of alkaline based material.
 5. The process as defined in claim 1, further comprising separating and recovering said water insoluble metal oxides from said porous matrix.
 6. The process as defined in claim 1, wherein said aqueous solution is continuously passed through said porous matrix at a rate of up to about 2 gallons of aqueous solution per cubic foot of porous matrix per day.
 7. The process as defined in claim 6, wherein the passing of said aqueous solution through said porous matrix containing said bacteria results in an increase in the pH level of said aqueous solution.
 8. The process as defined in claim 6, wherein the passing of said aqueous solution through said porous matrix containing said bacteria results in a decrease in the acidity level of said aqueous solution.
 9. The process as defined in claim 6, wherein the passing of said aqueous solution through said porous matrix containing said bacteria results in an increase in the alkalinity level of said aqueous solution.
 10. The process as defined in claim 6, wherein the passing of said aqueous solution through said porous matrix is carried out in the presence of at least one nutrient and in the presence of at least one trace nutrient.
 11. The process as defined in claim 10, wherein said at least one nutrient comprises at least one material selected from the group consisting of yeast extract, malt extract, peptone, cellulose, hemicellulose, hydrocarbons, pectin and pectin substances, starches, fructans, levans, inulins, sugars, proteins, amino acids, chitin, lignin, organic acids, derivatives of said materials, and biological and municipal waste water sludges.
 12. The process as defined in claim 11, wherein the passing of said aqueous solution through said porous matrix in the presence of said nutrients is carried out at a temperature ranging from about 32° F. to about 90° F.
 13. A process for reducing the concentration of water soluble metal ions in an aqueous solution containing the same, said process comprising the steps of:providing an aqueous solution having contained therein a concentration of water soluble metal ions; providing a porous matrix suitable for maintaining a population of aerobic metal oxidizing bacteria, said porous matrix being provided under aerobic conditions; inoculating said porous matrix with a population of aerobic metal oxidizing bacteria from the genus Metallogenium, wherein said bacteria is capable of metabolizing said water soluble metal ions in said aqueous solution into water insoluble metal oxides; and passing said aqueous solution through said porous matrix in a continuous fashion so as to allow said bacteria to metabolize said metal ions in said aqueous solution into water insoluble metal oxides which are substantially retained on said porous matrix, thereby resulting in a reduction in the concentration of said water soluble metal ions in said aqueous solution.
 14. The process as defined in claim 13, wherein said water soluble metal ions in said aqueous solution are manganese ions in the Mn (II) and Mn (IV) oxidation states and iron ions in the Fe (III) oxidation state.
 15. The process as defined in claim 13, wherein said aqueous solution is mine discharge water.
 16. The process as defined in claim 13, wherein said porous matrix is a porous matrix of alkaline based material.
 17. The process as defined in claim 13, further comprising separating and recovering said water insoluble metal oxides from said porous matrix.
 18. The process as defined in claim 13, wherein said step of passing said aqueous solution in a continuous fashion comprises allowing said aqueous solution to continuously flow through said porous matrix at a controlled rate of up to about 2 gallons of aqueous solution per cubic foot of porous matrix per day.
 19. The process as defined in claim 18, wherein said controlled rate is determined by gravity.
 20. The process as defined in claim 18, wherein said step of continuously passing said aqueous solution through said porous matrix results in an increase in the pH level of said aqueous solution.
 21. The process as defined in claim 18, wherein said step of continuously passing said aqueous solution through said porous matrix results in a decrease in the acidity level of said aqueous solution.
 22. The process as defined in claim 18, wherein said step of continuously passing said aqueous solution through said porous matrix results in an increase in the alkalinity level of said aqueous solution.
 23. The process as defined in claim 18, wherein said step of continuously passing said aqueous solution through said porous matrix is carded out in the presence of at least one nutrient and in the presence of at least one trace nutrient.
 24. The process as defined in claim 23, wherein said at least one nutrient comprises at least one material selected from the group consisting of yeast extract, malt extract, peptone, cellulose, hemicellulose, hydrocarbons, pectin and pectin substances, starches, fructans, levans, inulins, sugars, proteins, amino acids, chitin, lignin, organic acids, derivatives of said materials, and biological and municipal waste water sludges.
 25. The process as defined in claim 24, wherein said step of continuously passing said aqueous solution through said porous matrix in the presence of said nutrients is carried out at a temperature ranging from about 32° F. to about 90° F.
 26. A process for reducing the concentration of water soluble metal ions in a body of water containing the same, said process comprising the steps of:constructing a treatment zone in the form of a basin having an inlet port through which water from said body of water may flow into said basin and an outlet port through which water contained in said basin may flow out of said basin, said inlet port and said outlet port being located and configured so as to allow said water to flow substantially throughout the entirety of said basin at a controlled rate; filling said treatment zone with a porous matrix suitable for maintaining a population of aerobic metal oxidizing bacteria thereon; inoculating said porous matrix with a population of aerobic metal oxidizing bacteria from the genus Metallogenium, wherein said bacteria is capable of metabolizing said water soluble metal ions in said body of water into water insoluble metal oxides; and allowing water from said body of water to flow through said treatment zone, and hence through said porous matrix inoculated with said aerobic metal oxidizing bacteria from the genus Metallogenium, in a continuous fashion at said controlled rate so as to allow said bacteria to metabolize said water soluble metal ions in said flowing water into water insoluble metal oxides, thereby resulting in an overall decrease in the concentration of said water soluble metal ions in water flowing out of said treatment zone as compared to water flowing into said treatment zone.
 27. The process as defined in claim 26, wherein said water soluble metal ions in said flowing water are manganese ions in the Mn (II) and Mn (IV) oxidation states and iron ions in the Fe (III) oxidation state.
 28. The process as defined in claim 26, wherein said body of water is mine discharge water.
 29. The process as defined in claim 26, wherein said porous matrix is a porous matrix of alkaline based material.
 30. The process as defined in claim 26, further comprising separating and recovering said water insoluble metal oxides from said porous matrix.
 31. The process as defined in claim 26, wherein said step of allowing water from said body of water to flow through said treatment zone in a continuous fashion at said controlled rate comprises allowing water from said body of water to continuously flow through said treatment zone at a rate of up to about 2 gallons of water per cubic foot of porous matrix per day.
 32. The process as defined in claim 31, wherein said controlled rate is determined by gravity.
 33. The process as defined in claim 31, wherein said step of allowing water from said body of water to flow through said treatment zone in a continuous fashion at said controlled rate results in an increase in the pH level of said water.
 34. The process as defined in claim 31 , wherein said step of allowing water from said body of water to flow through said treatment zone in a continuous fashion at said controlled rate results in a decrease in the acidity level of said water.
 35. The process as defined in claim 31 wherein said step of allowing water from said body of water to flow through said treatment zone in a continuous fashion at said controlled rate results in an increase in the alkalinity level of said water. 